**Core Concept**
Muscle rigidity is a condition characterized by increased muscle tone, leading to stiffness and rigidity of the muscles. This condition can be caused by various factors, including pharmacological agents, neurological disorders, and metabolic disturbances.

**Why the Correct Answer is Right**
Haloperidol is a typical antipsychotic medication that acts as a dopamine receptor antagonist, primarily targeting D2 receptors in the striatum. By blocking dopamine receptors, haloperidol can cause extrapyramidal side effects, including muscle rigidity, dystonia, and parkinsonism. This is due to the disruption of the normal dopaminergic signaling in the basal ganglia, leading to an imbalance in motor control. The striatum, a key component of the basal ganglia, is responsible for regulating voluntary motor movements, and haloperidol's blockade of dopamine receptors in this region contributes to muscle rigidity.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while other antipsychotics may cause muscle rigidity, haloperidol is a well-known agent associated with this side effect.
**Option B:** This option is incorrect because it is not a pharmacological agent known to cause muscle rigidity.
**Option C:** This option is incorrect because it is not a correct agent associated with muscle rigidity.

**Clinical Pearl / High-Yield Fact**
When prescribing antipsychotic medications like haloperidol, it is essential to monitor patients for extrapyramidal side effects, including muscle rigidity, and adjust the dosage or switch to an atypical antipsychotic if necessary. Early recognition and management of these side effects can prevent long-term complications and improve patient outcomes.

**Correct Answer: C. Haloperidol**